As a conventional heat resistant wire etc., there is an MI cable, a fiber-glass braided wire, or a wire passing a ceramics tube. However, such a wire is bulky and disadvantageous in view of space. Further, the wire has such a disadvantage that its configuration is apt to be restricted to a round wire.
While a heat resistant organic wire whose surface is coated with an organic material is also known, such a wire cannot withstand a temperature exceeding 300.degree. C., and has a problem in heat resistance. Further, discharge of cracked gas, as well as discharge of adsorbed gas come into question.
As to a heat resistant wire, known are a method of applying a ceramics precursor which is prepared by a sol-gel method to a surface, and a Nippon Sheet Glass method [Liquid Phase Deposition (LPD) method]. However, these methods have such problems that it takes time for increasing film thicknesses.
Known is a method of applying a material which is obtained by mixing ceramics particles into silicone resin onto the surface of a wire or the like and thereafter heating/firing the same. According to this method, however, there is such a problem that the surface of the wire or the like is irregularized and roughened, and weakened against rubbing. It also has a problem in view of flexibility.
Also when films are formed by a spraying method and a sintering method, surfaces are irregularized or made porous. Thus, similar problems are caused.